It may happen that company negotiates currency contracts.

Then they may book transactions with fixed exchange rate (enter manually). These transactions should not be revaluated as part of currency contracts. The amount should not vary based on daily exchange rate.

Other scenario can be that invoices have different currencies. Customer may have input currency manually.

Payment is posted with total amount as per exchange rate from initial transactions.

When settlement is posted, then system should not generate exchange rate gain/loss as total in company currency is 0.

But so far, even if exchange rate is manually input on transactions, system considers the daily exchange rate during revaluation or settlement. Then artificial revaluation voucher is posted.

Workaround: when transactions is settled, amount in foreign currency should be marked as primary payment. Then no gain/loss amount is calculated.

But this has its limitation.